This proposal details a five-year plan to provide the candidate, William Sheehan, MD, with the knowledge and expertise to become an independent investigator in the field of Allergy and Immunology. The proposed research project is centered on a novel strategy of evaluating the amount of detectable environmental peanut protein exposure in childhood environments, such as homes, schools, and preschools. It has recently been theorized that avoidance of foods at a young age has contributed to the rise in food allergies, because children were instead becoming sensitized by cutaneous exposure to small amounts of food proteins in the environment. Dr. Sheehan presents preliminary data demonstrating detectable amounts of peanut protein (Ara h 2) in schools and homes. The candidate will use the established infrastructure of his mentor, Dr. Wanda Phipatanakul (current NIAID-funded study entitled School and Inner City Asthma Study); to further explore the study of peanut protein in the environment by analyzing vacuumed dust and table wipe samples. In addition to evaluating homes and schools, peanut-free preschools serving very young children will also be evaluated. Additionally, Dr. Sheehan will evaluate the effect of this environmental peanut exposure on health outcomes. Specifically, he will investigate the effect of exposure to environmental peanut protein on asthma morbidity with a particular focus on children considered to be at the highest risk of being affected by this cutaneous exposure. The at risk group will be defined by an enrolled subject with any one of the following conditions: (1) peanut allergy, (2) eczema, or (3) filaggrin gene mutation. Dr. Sheehan will work under the mentorship of Dr. Phipatanakul, an expert in environmental exposures and the relationship with allergic diseases. Dr. Sheehan has also assembled a team of extraordinary researchers, including Drs. Diane Gold, Raif Geha, and Brent Coull, who have committed their time, resources, and expertise to facilitate his career development and research goals. During the period of support for the candidate, he will engage in formal education on clinical research by obtaining a Master of Medical Sciences (MMSc) degree from the Scholars in Clinical Science Program at Harvard Medical School. This program will provide him with further skills in advanced biostatistics, epidemiology, clinical study design, clinical genetics, and scientific writing. Under the guidance of his primary mentor and collaborative team, in an ideal scientific and clinical environment at Boston Children's Hospital, the research project and career development plan will position the candidate to secure independent NIH funding and to establish himself as an independent clinical researcher in the field of environmental food exposures and allergic diseases, a relatively neglected area of investigation.